Douglas Beicht, 42, had been accused of rubbing up against the victim’s backside in a sexual manner while their pants were down at the Hudson Plaza Motel on the Jersey City-Bayonne border, authorities said.

Beicht and the victim’s family each had rooms at the motel on Dec. 16 when the incident occurred in Beicht’s room, Hudson County Deputy First Assistant Prosecutor Debra Simon said.

Beicht was arrested a week later when the victim told his mother and she contacted Bayonne police.

He pleaded guilty Monday to second-degree sexual assault by contact.

Under his plea agreement, he faces seven years in prison when he is sentenced Sept. 6 at 9 a.m. in Rose’s courtroom, and he must serve 85 percent of his sentence before being eligible for parole.